The Research Of Micromanipulation System With Servo Control Base On The Microscopic Vision

Recent years,many micro manipulation system or micro manipulation hand apply to military affairs,optics communication,biology and precision mechanism,and these also have success.So these application field also advance more requirement to micro-manipulation system,for example:motion precision,respond speed,force sense,control and flexible.Some project application field not only require large workspace,but also ultra-precision.Some others projects require micro-manipulation system has fast motion speed and precision force sense.All these requirements make the traditional micro-manipulation system with single drive method can not accomplish the appointed task.At the same time microscopic vision is fundamental important to Micromanipulation which provide lower level and non-contact feedback information to control system,include microscale geometry,spatial relations and motion of micro-components.Because of particular properties of microscopic vision,which often suffer from small field of vision and limitied depth of focus.It is important to study that How to conquer the disadvantage from above.In order to resolve above problems,at the end of the twenty century eighty,many scholars of the word put forward macro-micro dual drive micro-manipulation system.In the past twenty years,not only theory prove but also project application both prove that macro-micro dual drive micro manipulation system has many merits over the traditonal single drive micro-manipualtion system.,it is a valid method to resolve large workspace and ultra-precision.The paper mainly research the macro-micro dual drive micro manipulation system based on mechine vision.It adopts motor and silk-bar framework to fabricate the macrostage with large workspace and large drive force etc;its microstage is made of PZT,because PZT has many merits,for example fast response,high precision and frictionless etc characters.So the micro manipulation system at the same time has large workspace and nano precision.In the microscopic feedback progress of micromanipulation,we can acquire in focus image and our of focus image in the same time.It can make some area of target image is clear and the others is blur.We adopt the microscopic auto focus technology base on image definition.A image definition method was developed,which combine the image definition base on traditional grads and the image definition base on wavelet transformation.This technology can provides high response speed,significantly better depth resolution and accuracy.We adobe the target area select method to carry out autofocus for avoid system focus on non-target area.For acquire a clear image of entire target,must used different method of sequence image fusion for different type target.A image fusion method base on wavelet transform was adobed for the target that can be aquire the shape and character.this may generate some distortion,but can not influence the result of judgement of system operate progress,this method can get a good control effect to the micromanipulation system.The other image fusion method base on the same coordinate pixel of sequence image definition evaluate was adobed for the target that can not permit distortion(for example:Cell observe).This method can not increase calculation distortion compare with the clear origin image in the sequence image,that can ensure system work normally.According to the different character of target adobe different tracking arithmetic to resolve the problem of the damage to the system performance of tracking if digital image process result in time delay.Used the area pattern matching fast tracking arithmetic to tracking the target which cannot change the shape(for example:operate-tool,clamp-tool, mechanism part).For the target that maybe change the shape and character in the tracking progress,cannot get the pattern of target beforehand,used the digital matting technology to recognise contour of target and provide the coordinate message of target to the control and decision-making system.The experiment results showed that arithmetics not only improve the system response speed but also ensure the accuracy of tracking.At the same time,we aim at many micro manipulaiton system has trouble in harmonizing control,put forward adopting mahine vision to harmonize each control part of macro and micro.The system looks at the distance between the implement and target as control threshold,if the threshold more than the threshold,the control part start up the macrostage and macro control part,or else,start up the microstage and PZT control part in order to compensate the displacement error.At last,we make use of LabVIEW to design the vision servo programe realizing track,recognising and control.At last,the paper has the background of cell injection of biology project,and design machine vision track and recogniseing programe,and home research those key technology.The system have realized dynamicly recognising injection needle and cell,and truly control microstage motion to appointed place;at the same time,the system has dyanmic place and the distance between needle and cell saving to the appointed database.Experiment result shows the micro manipulation system working stabilization,track,recognising, positioning and control all have achieved anticipative aim.